Field of the Invention
The present invention relates to a table clamp device and a pallet changer.
Discussion of the Background
Conventionally, there is known a pallet changer that holds out/pulls in or exchanges, between a machining position and a setup position of a machine tool, a pallet on which a workpiece is mounted, by rotation around a predetermined rotary shaft.
As typical examples of the structure of such a pallet changer, those described in Japanese Unexamined Patent Application Publication No. 2002-137136 and Japanese Unexamined Patent Application Publication No. 07-040180 are known.
A pallet exchange device described in Japanese Unexamined Patent Application Publication No. 2002-137136 includes a rotary table that rotates 180 degrees between a machining position and a setup position of a machine tool, two pallets disposed on the rotary table, clamp blocks provided on lower surfaces, of the rotary table, where the two pallets are mounted, and clamp bases provided at the machining position and the setup position, respectively.
Moreover, the pallet exchange device of Japanese Unexamined Patent Application Publication No. 2002-137136 is configured such that, when one of the pallets is disposed at the machining position, a positioning pin protrudes from the clamp base at the machining position into the clamp block to perform positioning, and also such that a claw member of the clamp base presses and fixes the clamp block in a manner of pressing down.
A pallet support device described in Japanese Unexamined Patent Application Publication No. 07-040180 includes a rotary arm that rotates between a changeover board and a pallet rotation mechanism provided at a machining position and that moves up and down, a clamp device provided to the pallet rotation mechanism, a tapered socket formed on a lower surface of a pallet supported by the rotary arm, a pull stud protruding at the center of the tapered socket, a tapered cone formed on an upper surface of the clamp device, and an insertion hole formed at the center of the tapered cone.
Furthermore, the pallet support device of Japanese Unexamined Patent Application Publication No. 07-040180 is configured such that the pallet is positioned by the clamp device by the tapered socket being engaged with the tapered cone according to the vertical movement of the rotary arm, and also such that the pull stud protruding from the tapered socket is inserted and fixed in the insertion hole of the tapered cone, and solid clamping is thereby achieved.